Multilayer impact resistant hockey stick

ABSTRACT

A multilayer hockey stick is provided having improved impact resistant and energy absorbing characteristics. The hockey stick includes a shaft having a body, an energy absorbing layer and an impact resistant layer. The energy absorbing layer and impact resistant layer are applied to select areas of the shaft of the hockey stick which are prone to failure due to stick-to-stick contact.

FIELD OF THE INVENTION

[0001] The present invention relates generally to hockey sticks, andmore particularly to a hockey stick having improved impact resistanceand energy absorbing characteristics.

BACKGROUND OF THE INVENTION

[0002] The popularity of sporting events in today's society has prompteda wide movement in the development of sports equipment. In most sportingevents there is a need to develop equipment that exhibits maximumperformance while minimizing production costs. One way of altering thedevelopment of equipment lies in the selection of materials used tomanufacture the equipment. The combination of materials used to design avariety of sports equipment continues to provide advancements in thetechnology.

[0003] One particular aspect of sports equipment design is focused onstrengthening particular structural components of the equipment. Thistype of development may be applied to a variety of sporting events whichutilize shafts such as bats, rackets, and sticks. For example, suchshafts are utilized in hockey, baseball, lacrosse, and tennis, amongothers.

[0004] Hockey is one sport in which equipment design has continued todevelop. Although the functionality of a hockey stick has remainedconstant over time, the design and manufacture of hockey sticks hascontinued to progress and change due to the variety of materials nowbeing used in the industry. Materials used in the manufacturing ofhockey sticks are modified not only due to the desired physicalcharacteristics of the hockey sticks, but various performancecharacteristics as well.

[0005] A hockey stick must be lightweight and have a strengthsubstantial enough to endure the stresses that occur during use. Moreparticularly, the hockey stick should be able to endure the primarystresses that develop in the shaft of the hockey stick, especially themaximum stress that occurs towards the shaft/blade interface when stickscome into contact in play. The flexibility of a hockey stick is anadditional performance characteristic that is desirable, due to theimportance of the hockey stick having the ability to provide enough“flex” during wrist shots and slap shots for the user to maximize shotvelocity and control.

[0006] Hockey sticks can be made from a variety of materials, includingwood, aluminum, plastic, fiberglass, carbon, KEVLAR®, or combinationsthereof. Traditionally, the selection of materials is primarily based onthe weight, stiffness and cost of each of the materials. Compositeshafts are somewhat expensive and have poor durability, but are stillpopular primarily due to their light weight. Wood shafts are relativelyinexpensive, however, they are not especially lightweight, stiff ordurable. Aluminum shafts are somewhat less reliable due to the fact thatbending failures frequently occur within the shaft.

[0007] In view of the foregoing, it can be appreciated that there is acontinuing need to develop hockey sticks which are inexpensive,lightweight, durable, impact resistant, and flexible. As the popularityof hockey continues, the technology of the equipment must continue todevelop as well.

SUMMARY OF THE INVENTION

[0008] One object of the present invention is to provide a shaft and amethod for making the same which has a reinforced section that exhibitsincreased durability and strength.

[0009] Another object of the present invention is to provide a shaft andmethod for making the same which has a reinforced section that includesan energy absorbing layer and an impact resistant layer.

[0010] In particular, one aspect of the present invention provides ahockey stick and method of making the same that includes a shaft havinga body, an energy absorbing layer and an impact resistant layer. Theenergy absorbing layer and impact resistant layer are applied to selectareas of the shaft of the hockey stick which benefit from reinforcementor are prone to damage due to use.

[0011] Another aspect of the present invention improves durability oflightweight hockey sticks, while at the same time maintaining therectangular geometry of the stick. This is obtained by wrapping anenergy absorbing layer around the body of the shaft and snapping orsliding an impact resistant sleeve around the energy absorption materialand shaft body.

[0012] Further areas of applicability of the present invention willbecome apparent from the detailed description provided hereinafter. Itshould be understood however that the detailed description and specificexamples, while indicating preferred embodiments of the invention, areintended for purposes of illustration only, since various changes andmodifications within the spirit and scope of the invention will becomeapparent to those skilled in the art from this detailed description.

BRIEF DESCRIPTION OF THE DRAWINGS

[0013] The various advantages of the present invention will becomeapparent to one skilled in the art by reading the followingspecification and subjoined claims and by referencing the followingdrawings in which:

[0014]FIG. 1 is a perspective view of a preferred embodiment of a hockeystick of the present invention having a reinforced portion of the shaft;

[0015]FIG. 2 is a cross-sectional view taken along section line 2-2 ofFIG.

[0016]FIG. 3a is a longitudinal cross-sectional view of the preferredembodiment of a hockey stick of the present invention 1;

[0017]FIG. 3b is a longitudinal cross-sectional view of an alternateembodiment of a hockey stick of the present invention;

[0018]FIG. 3c is a longitudinal cross-sectional view of anotheralternate embodiment of a hockey stick of the present invention;

[0019]FIG. 4a is a perspective view of the present inventiondemonstrating a method of applying the energy absorbing layer to theshaft body of the hockey stick;

[0020]FIG. 4b is an exploded view showing the relation of the impactresistant layer to the shaft body wrapped with the energy absorbinglayer;

[0021]FIG. 4c is a perspective view of the present invention having theimpact resistant layer outboard of the energy absorbing layer of theshaft body;

[0022]FIG. 5 is an exploded view of a circumferentially enclosedpolycarbonate sleeve positioned to be telescopically received by theshaft body;

[0023]FIG. 6 is a cross-sectional view of yet another alternateembodiment of the present invention; and

[0024]FIG. 7 is a perspective view of still yet another alternateembodiment of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0025] Referring first to FIG. 1, a hockey stick 10 is divided intothree areas; a blade 12, a shaft 14 and an end plug 16. It is withineach of these structural areas of the hockey stick 10 that variousimprovements are implemented in order to enhance the performancecharacteristics of the hockey stick 10. The present invention focusesprimarily on the shaft 14 of the hockey stick 10 and certainmodifications therein.

[0026] In general, the shaft 14 of the hockey stick 10 has a first end18 opposite a second end 20. The first end 18 of the shaft 14 is foundwhere the shaft 14 is coupled with the blade 12 of the hockey stick 10.The second end 20 of the shaft 14 is found where the shaft 14transitions to the end plug 16. Many of the stresses that occur to ahockey stick during use occur at locations proximate to where the blade12 and the shaft 14 meet. Stress regions are exhibited along the shaft14 due to the large amount of stick-to-stick and stick-to-ice contactoccurring during usage. One particular high stress region, known as theslash zone, is located proximate the first end 18 of the shaft 14. Morespecifically, the slash zone is located within the lower portion 22 ofthe shaft 14. Although high stress regions primarily occur in the lowerportion 22 of the shaft, occasional stress areas may occur within theupper portion 24 of the shaft 14 proximate the second end 20 due toplayer to player contact.

[0027] In order to improve the durability and impact resistance of thehockey stick 10 at various stress regions along the shaft 14, it isdesirable to apply supplemental layers.

[0028] As can be seen in FIG. 2, which is a cross-sectional view of theshaft 14 of hockey stick 10 taken along lines 2-2 of FIG. 1, a pluralityof reinforcing layers surround the shaft 14. The shaft 14 includes abody 26 longitudinally extending the entire length of the shaft 14. Thebody 26 of hockey stick 10 can be comprised of various materials, whichmay include but are not limited to wood, composite, various metals,fiberglass, plastic, KEVLAR®, carbon and combinations thereof.

[0029] An energy absorbing layer 28 is disposed on the outer surface ofthe body 26. The energy absorbing layer 28 is a cushioning materialwhich provides an energy absorption medium along prescribed regions ofthe shaft 14. The energy absorbing layer 28 is preferably made of aviscoelastic material which may include but is not limited to a varietyof viscoelastic damping polymers, such as VHB®, Sorbothane®, T-lastic®,etc. The energy absorbing layer 28 is preferably approximately 0.015inches to 0.025 inches thick. Although this particular thickness isgenerally preferred, the thickness of the energy absorbing layer 28 maybe varied according to the particular stresses expected to be endured.

[0030] The preferred embodiment of the present invention employs 3M'sVHB® tape as the energy absorbing layer. The VHB® tape is a double-sidedviscoelastic tape 28 a having an acrylic adhesive 29 a, 29 b on eachside. The acrylic adhesive is an aggressive adhesive which secures theenergy absorbing layer 28 to the body of the shaft. Although VHB® tapeis currently being used, alternate types of energy absorbing materialmay be used in combination with various adhesives, if desired.

[0031] The outer perimeter of the shaft 14 is enclosed by an impactresistant layer 30. The impact resistant layer 30 preferably has anannular or sleeve-like configuration. The impact resistant layer 30 ismost preferably composed of a polycarbonate material, such as LEXAN®(available from the General Electric Company), although apolycarbonate/ABS blend may also be used. The impact resistant layer 30is preferably approximately 0.010 inches to 0.020 inches thick.Furthermore, the impact resistant layer 30 is preferably transparent,although a tint or full color embodiment may also be employed. Thedesign of the impact resistant layer 30 allows the sleeve to be appliedto the shaft of the hockey stick relatively easy. One preferredembodiment, as described below, provides a polycarbonate sleeve having alongitudinal slit 32 extending along the entire length of the sleeve.The longitudinal slit 32 provides a means for expanding the sleeve suchthat it snaps or slides over the shaft 14 of the hockey stick 10.

[0032] As seen in FIG. 2, the impact resistant layer 30 preferablyincludes a slightly thicker portion of polycarbonate material adjacentthe corners of the shaft 14. The additional material present in thecorners of the shaft 14 enhances protection to the hockey stick whereimpact is most likely to occur. This slight modification provides theimpact resistant layer 30 with a more durable configuration.

[0033] In addition to the multiple layers described above, variousdecals or designs may be added to the body of the shaft. The preferredapplication of a decal is provided by bonding the decal onto the acrylicadhesive 29 a present on the outer surface of the energy absorbinglayer. A transparent polycarbonate impact resistant layer 30 is thenplaced over the decal in order to provide impact resistance for thehockey stick 10. The transparent polycarbonate layer allows the decal tobe viewed through the sleeve.

[0034] FIGS. 3A-3C demonstrate various applications of the energyabsorbing layer 28 and the impact resistant sleeve 30 to the shaft 14 ofthe hockey stick 10 and the various preferred embodiments.

[0035]FIG. 3A is a longitudinal cross-sectional view illustrating theapplication of the energy absorbing layer 28 and the impact resistantlayer 30 to the lower portion 22 of the shaft 14.

[0036]FIG. 3B is a longitudinal cross-sectional view illustrating theapplication of the energy absorbing layer 28 and the impact resistantlayer 30 to the lower portion 22 and the upper portion 24 of the shaft14.

[0037]FIG. 3C is a longitudinal cross-sectional view illustrating theextension of the energy absorbing layer 28 and the impact resistantlayer 30 from the lower portion 22 through the upper portion 24 andalong the end plug 16. In general, the energy absorbing layer 28 and theimpact resistant layer 30 may be applied anywhere along the body 26 ofthe shaft 14 and at various lengths. Therefore, the length of the energyabsorbing layer 28 and impact resistant layer 30 applied to the body 26of the shaft 14 is preferably based upon the desired performance of thehockey stick 10.

[0038] A preferred method of preparing the present invention isillustrated in FIGS. 4A-4C. Initially, a shaft body 26, which is usuallyrectangularly shaped, is provided. Next, the energy absorbing layer 28having a sheet-like configuration is applied to the shaft body 26. Asseen in FIG. 4,A the energy absorbing layer 28 has a width substantiallythe same as the circumference of the shaft body 26. The length of theenergy absorbing layer 28 may vary depending on the desired region ofthe shaft body 26 covered. The energy absorbing layer 28 is foldedaround the circumference of the shaft body 26 thereby providing acontinuous layer around the wrapped region of the shaft body 26, as seenin FIG. 4A. The wrapping of the double-sided viscoelastic tape 28 bondsthe interior side of the viscoelastic tape 28 to the outboard surface ofthe shaft body 14. Alternate methods may be used for applying theviscoelastic layer to the shaft body 14, such as helically wrapping theviscoelastic tape in a longitudinal direction along the shaft.

[0039] Although not shown in the figures, if desired, a decal or designbearing emblem may then be disposed on the outer surface of theviscoelastic tape. The bonding of the decal to the viscoelastic tape ispreferably accomplished through use of the acrylic adhesive on the outersurface of the tape 28.

[0040] Following the positioning of the viscoelastic tape and theapplication of the decal or design to the outer surface of theviscoelastic tape, the impact resistant layer 30 is applied to the shaftbody 14. Preferably, the impact resistant layer 30 is provided in theform of an annular sleeve 30 which is snapped over the body 26 of theshaft 14 by forcing the body 26 through the longitudinal slit 32 therebyexpanding the sleeve. As seen in FIG. 4b, the longitudinal slit 32provides a passage to an axial bore 34 formed throughout the impactresistant sleeve 30 for accommodating the shaft body 14. Following theplacement of the impact resistant sleeve 30 around the body shaft 14 asseen in FIG. 4c, a polyurethane tape 36 is placed along the longitudinalslit 32 to secure the placement of the impact resistant sleeve 30. Asection of polyurethane tape 36 may be applied around the opposing endsof the impact resistant sleeve in order to encapsulate the multilayeredregion of the shaft body.

[0041] As seen in FIG. 5, an alternate embodiment impact resistant layer30′ and method for mounting the layer 30′ to the shaft 14′ isillustrated. In this embodiment, the layer 30′ takes the form of acircumferentially enclosed polycarbonate sleeve (not having a slit).Following the application of the viscoelastic tape 28′ and bonding of adecal (if desired), the polycarbonate sleeve 30′ having an axial bore34′ formed therethrough is telescopically slid over the shaft body 26′.Various lubricants may be used to assist in the receipt of the shaftbody 26′ within the bore 34′ of the polycarbonate sleeve 30′. Upon theplacement of the shaft body 26′ within the polycarbonate sleeve 34′,polyurethane tape 36′ may be used to affix the ends of the polycarbonatesleeve 34′ to the shaft body 26′.

[0042]FIG. 6 illustrates a cross-sectional view of an alternateembodiment of the present invention which provides a shaft 14″ of thehockey stick 10″ having an impact resistant layer 30″ applied directlyon the body 26″. This embodiment enhances the impact resistance of theshaft 14″, without modifying the energy absorption characteristics ofthe shaft 14″.

[0043] A further alternate embodiment, as seen in FIG. 7, provides ahockey stick 50 having a shaft 52 with a body 54 containing a recessedportion 56 annularly formed around the body 54 of the shaft 52. Therecessed portion 56 is provided for concentrically accommodating theenergy absorbing layer 28 and impact resistant layer 30 along the body54 of the shaft 52. In the previously described embodiments of thepresent invention, the application of the energy absorbing layer and theimpact resistant layer form a small ridge around the exteriorcircumference of the shaft. Depending on the desired length of thespecific layers applied, the ridge formed by the ends of the energyabsorbing layer and the impact resistant layer may be disfavored bycertain players. In order to obtain a coplanar (smooth) external surfacealong the shaft 52 of the hockey stick 50, the energy absorbing layer 28and the impact resistant layer 30 are applied within the recessedportion 56 provided in the body 54 of the shaft 52 as previouslydescribed in the alternate embodiments. The depth of the recessedportion 56 is selected to match the thickness of the energy absorbinglayer 28 and impact resistant layer 30 (and any adhesive used incombination therewith) if both layers are employed, or the impactresistant layer 30 (and any adhesive) if only the impact resistant layer30 is employed. As such, the recessed portion 56 of the body 54 providesthe player with a planar shaft 52. The recessed portion 56 is preferablyformed when molding the shaft 52 although other methods such as grindingmay be used.

[0044] The invention being thus described, it will be obvious that thesame may be varied in many ways. Such variations are not to be regardedas a departure from the spirit and scope of the invention, and all suchmodifications as would be obvious to one skilled in the art are intendedto be included within the scope of the following claims.

What is claimed is:
 1. An apparatus for playing sports having a shaft-like portion, said shaft-like portion comprising: a body; an energy absorbing layer disposed adjacent to said body; and an impact resistant layer disposed adjacent to said energy absorbing layer.
 2. The apparatus for playing sports according to claim 1, wherein said body is selected from the group consisting of wood, composite, metals, fiberglass, plastic, KEVLAR®, carbon and combinations thereof.
 3. The apparatus according to claim 1, wherein said energy absorbing layer further comprises a viscoelastic layer.
 4. The apparatus according to claim 3, wherein said viscoelastic layer further comprises a viscoelastic tape disposed about said body.
 5. The apparatus according to claim 4, wherein said impact resistant layer further comprises a polycarbonate material.
 6. The apparatus according to claim 5, wherein said impact resistant layer further comprises a polycarbonate sleeve disposed over said body.
 7. The apparatus of claim 6, wherein said polycarbonate sleeve includes corners having more polycarbonate material than between said corners.
 8. The apparatus according to claim 1, wherein said body further comprises a recessed portion accommodating at least one of said energy absorbing layer and said impact resistant layer.
 9. The apparatus according to claim 8, wherein said recessed portion extends annularly around said body.
 10. The apparatus according to claim 8, wherein a depth of said recessed portion is substantially equal to a thickness of the energy absorbing layer and the impact resistant layer.
 11. The apparatus according to claim 8, wherein said impact resistant layer is substantially coplanar with an external surface of said body.
 12. A hockey stick comprising: a shaft having a first end and a second end; and a blade adjacent said first end of said shaft; wherein said shaft of said hockey stick includes a body and an impact resistant layer coupled to body.
 13. The hockey stick according to claim 12 further comprising an energy absorbing layer disposed between said body and said impact resistant layer.
 14. The hockey stick according to claim 13 wherein said energy absorbing layer substantially encircles said body of said shaft.
 15. The hockey stick according to claim 14 wherein said impact resistant layer substantially encircles said energy absorbing layer.
 16. The hockey stick according to claim 15 wherein said impact resistant layer further comprises a polycarbonate layer.
 17. The hockey stick according to claim 16 wherein said energy absorbing layer further comprises a viscoelastic layer.
 18. The hockey stick according to claim 13 wherein said impact resistant layer and said energy absorbing layer are disposed adjacent a lower portion of said shaft proximate said first end.
 19. The hockey stick according to claim 13 wherein said impact resistant layer and said energy absorbing layer are disposed adjacent an upper portion of said shaft proximate said second end.
 20. The hockey stick according to claim 13, wherein said impact resistant layer and said energy absorbing layer are disposed substantially along said shaft between said first end and said second end.
 21. A method of preparing a shaft comprising the steps of: providing a shaft body; securing an energy absorbing layer to said body; and securing an impact resistant layer to said energy absorbing layer.
 22. The method according to claim 21 wherein said step of securing said energy absorbing layer to said body further comprises wrapping an energy absorbing tape around said body.
 23. The method according to claim 22 wherein said step of wrapping said energy absorbing layer around said body further comprises wrapping a viscoelastic layer around said body.
 24. The method according to claim 23, wherein said viscoelastic layer has a width substantially the same as a circumference of the shaft body.
 25. The method according to claim 24 wherein said step of securing said impact resistant layer to said energy absorbing layer further comprises disposing an impact resistant sleeve over said energy absorbing layer.
 26. The method according to claim 25 wherein said step of disposing said impact resistant sleeve over said energy absorbing layer further comprises snapping said impact resistant sleeve over said shaft body via a longitudinal slot formed in said impact resistant sleeve.
 27. The method according to claim 25 wherein said step of disposing said impact resistant sleeve over said energy absorbing layer further comprises telescopically sliding said impact resistant sleeve over said shaft body. 